Fold out ramp

ABSTRACT

A ramp assembly provides a transition surface from a vehicle floor to an alighting surface and includes a ramp portion coupled for reciprocating movement between a stowed position and a deployed position. The ramp portion has a cam surface disposed thereon, and a cam follower that engages the cam surface when the ramp portion is in the stowed position to support the ramp portion. The ramp assembly further includes a panel rotatably coupled to a first end of the ramp portion about an axis. An actuator rotates a drive arm to move the ramp portion through first and second phases of a deployment motion. During the first phase, the drive arm rotates the ramp portion about the axis, which maintains a substantially fixed position. During the second phase, the drive arm moves the second axis in a downward direction.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 13/454,858,filed on Apr. 24, 2012, which is a continuation-in-part of U.S. patentapplication Ser. No. 13/350,642, filed Jan. 13, 2012, and issued as U.S.Pat. No. 8,250,693 on Aug. 28, 2012, which is a continuation-in-part ofU.S. patent application Ser. No. 13/015,439, filed Jan. 27, 2011, andissued as U.S. Pat. No. 8,132,281 on Mar. 13, 2012, the disclosures ofwhich are expressly incorporated by reference. U.S. patent applicationSer. No. 13/454,858 also claims the benefit of U.S. ProvisionalApplication No. 61/596,117, filed Feb. 7, 2012, the disclosure of whichis expressly incorporated by reference.

BACKGROUND OF THE INVENTION

The Americans with Disabilities Act (ADA) requires the removal ofphysical obstacles to those who are physically challenged. The statedobjective of this legislation has increased public awareness and concernover the requirements of the physically challenged. Consequentially,there has been more emphasis on providing systems that enable physicallychallenged people to access a motor vehicle, such as a bus or minivan.

A common manner of providing the physically challenged with access tomotor vehicles is a ramp. Various ramp operating systems for motorvehicles are known in the art. Some slide out from underneath the floorof the vehicle and tilt down. Others are stowed in a vertical positionand pivot about a hinge, while still others are supported by booms andcable assemblies. The present invention is generally directed to a “foldout” type of ramp. Such a ramp is normally stowed in a horizontalposition within a recess in the vehicle floor, and is pivoted upward andoutward to a downward-sloping extended position. In the extendedposition, the ramp is adjustable to varying curb heights.

Fold out ramps on vehicles confront a variety of technical problems.Longer ramps are desirable because the resulting slope is more gradualand more accessible by wheelchair-bound passengers. Longer ramps are,however, heavier and require more torque about the pivot axis to bereciprocated between deployed and stowed positions. To satisfy theincreased torque requirement, some fold out ramps use large electricmotors, pneumatic devices, or hydraulic actuators to deploy and stow theramp. Often, these systems cannot be moved manually in the event offailure of the power source, unless the drive mechanism is firstdisengaged. Some existing fold out ramps can be deployed or stowedmanually, but they are difficult to operate because one must firstovercome the resistance of the drive mechanism. Further, fold out rampsrequire a depression (or pocket) in the vehicle's vestibule floor inwhich to store the retracted/stowed ramp. When the ramp is deployed, theaforementioned depression presents an obstacle for wheelchair passengersas they transition from the ramp to the vestibule, and into the vehicle.

Another technical issue confronting fold out ramps is the variety ofsituations in which the ramps must operate. Depending on the use of thevehicle in which a particular ramp is installed, the ramp might bedeployed to curbs of varying heights, as well as to a road surface. Inaddition, road crown, the inclusion of a “kneeling” feature on thevehicle, and other factors can affect the height of the vehicle floorrelative to the alighting surface. Thus, the vertical distance thoughwhich a ramp must provide a transition surface can vary significantly.

In view of the foregoing, there is a need for a fold out ramp for avehicle that provides a longer ramp surface to reduce the ramp angle ina variety of situations, and comprises an interior surface coplanar withthe adjacent vehicle floor, and further includes a compact and efficientoperating system.

SUMMARY

Various embodiments of a ramp assembly for providing a transitionsurface between a vehicle floor and an alighting surface are disclosed.In a first embodiment, the ramp assembly comprises a ramp portioncoupled for reciprocating movement between a stowed position and adeployed position. A cam surface is disposed on the ramp, and a camfollower engages the cam surface when the ramp portion is in the stowedposition to support the ramp portion. The ramp assembly further includesa panel rotatably coupled about an axis to a first end of the rampportion. An actuator rotates a drive arm to move the ramp portionthrough first and second phases of a deployment motion. During the firstphase, the drive arm rotates the ramp portion about the axis, whichmaintains a substantially fixed position. During the second phase, thedrive arm moves the axis in a downward direction.

A second disclosed embodiment of a ramp assembly includes a ramp portioncoupled for rotational movement between a stowed position and a deployedposition. The ramp portion has side curb with a cam surface disposedthereon. A panel is rotatably coupled to the ramp portion about a firstaxis. The ramp portion further includes an elongate drive arm operablycoupled to the ramp portion and extending radially from a second axis.An actuator rotates the drive arm about the second axis to move the rampportion through a deployment motion. The deployment motion has a firstphase, during which the drive arm rotates the ramp portion about thefirst axis, and a second phase, during which the drive arm moves thefirst axis from a raised position to a lowered position. The rampassembly also includes a cam follower that engages the cam surface whenthe ramp portion is in the stowed position to support the ramp portion.

In a third exemplary embodiment, a ramp assembly has a ramp portioncoupled for rotational movement between a stowed position and a deployedposition, wherein the ramp portion includes a cam surface. A first panelis rotatably coupled to the ramp portion about a first axis and isrotatably associated with a second panel. The second panel reciprocatesbetween a lowered position when the ramp portion is in the stowedposition, and a raised position when the ramp portion is in the deployedposition. A cam follower engages the cam surface when the ramp portionis in the stowed position to support the ramp portion. The cam followeris disengaged from the cam surface when the ramp portion is in thedeployed position.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features ofthe claimed subject matter, nor is it intended to be used as an aid indetermining the scope of the claimed subject matter.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an isometric view of an exemplary embodiment of a rampassembly with a ramp portion in the stowed position;

FIG. 2 is an isometric view of the ramp assembly shown in FIG. 1, withthe ramp portion in a neutral position;

FIG. 3 is an isometric view of the ramp assembly shown in FIG. 1, withthe ramp portion in a first deployed position;

FIG. 4 is an isometric view of the ramp assembly shown in FIG. 1, withthe ramp portion in a second deployed position;

FIG. 5 is a side view of the ramp assembly shown in FIG. 1, with theramp portion in the stowed position;

FIG. 6 is a side view of the ramp assembly shown in FIG. 1, with theramp portion in a neutral position;

FIG. 7 is a side view of the ramp assembly shown in FIG. 1, with theramp portion in a first deployed position;

FIG. 8 is a side view of the ramp assembly shown in FIG. 1, with theramp portion in a second deployed position;

FIG. 9 is a partial cross-sectional view of the ramp assembly shown inFIG. 1, wherein a latch mechanism is shown with the ramp portion in afirst deployed position;

FIG. 10 is a partial cross-sectional view of the ramp assembly shown inFIG. 1, wherein a latch mechanism is shown with the ramp portion in asecond deployed position;

FIG. 11 is partial isometric view of the ramp assembly shown in FIG. 1,with an intermediate panel and an inner panel removed;

FIG. 12 is a partial side view of the ramp assembly shown in FIG. 1,showing a drive arm when the ramp portion is in the stowed position;

FIG. 13 is a partial side view of the ramp assembly shown in FIG. 1,showing the drive arm when the ramp portion is in a neutral position;

FIG. 14 is a partial side view of the ramp assembly shown in FIG. 1,showing the drive arm when the ramp portion is in a first deployedposition;

FIG. 15 is a partial side view of the ramp assembly shown in FIG. 1,showing the drive arm when the ramp portion is in a second deployedposition;

FIG. 16 is an isometric view of a second exemplary embodiment of a rampassembly with a ramp portion in the stowed position;

FIG. 17 is an isometric view of the ramp assembly shown in FIG. 16, withthe ramp portion in a neutral position;

FIG. 18 is an isometric view of the ramp assembly shown in FIG. 16, withthe ramp portion in a first deployed position;

FIG. 19 is an isometric view of the ramp assembly shown in FIG. 16, withthe ramp portion in a second deployed position;

FIG. 20A is a partial side view of the ramp assembly shown in FIG. 16,showing a linkage when the ramp portion is in the stowed position;

FIG. 20B is a partial side view of the ramp assembly shown in FIG. 16,showing a cam surface and cam follower when the ramp portion is in thestowed position;

FIG. 21A is a partial side view of the ramp assembly shown in FIG. 16,showing the linkage when the ramp portion is in a neutral position;

FIG. 21B is a partial side view of the ramp assembly shown in FIG. 16,showing the cam surface and cam follower when the ramp portion is in aneutral position;

FIG. 22A is a partial side view of the ramp assembly shown in FIG. 16,showing the linkage when the ramp portion is in a first deployedposition;

FIG. 22B is a partial side view of the ramp assembly shown in FIG. 16,showing the cam surface and cam follower when the ramp portion is in afirst deployed position;

FIG. 23A is a partial side view of the ramp assembly shown in FIG. 16,showing the linkage when the ramp portion is in a second deployedposition; and

FIG. 23B is a partial side view of the ramp assembly shown in FIG. 16,showing the cam surface and cam follower when the ramp portion is in asecond deployed position.

DETAILED DESCRIPTION

Exemplary embodiments of the disclosed fold out ramp will now bedescribed with reference to the accompanying drawings, where likenumerals correspond to like elements. The described embodiments aredirected to ramp assemblies, and more specifically, wheelchair rampassemblies. In particular, several embodiments are directed towheelchair ramp assemblies suitable for use in buses, vans, etc. Severalembodiments of the present invention are directed to compact rampassemblies for a vehicle that, when stowed, occupy a small amount ofspace within the vehicle floor, yet deploy to a length that effectivelyreduces the ramp slope encountered by the mobility impaired, thusfacilitating greater independence and safety for wheelchair-boundpassengers.

The following discussion proceeds with reference to examples ofwheelchair ramp assemblies for use in vehicles having a floor, such as abus, van, etc. While the examples provided herein have been describedwith reference to their association with vehicles, it will be apparentto one skilled in the art that this is done for illustrative purposesand should not be construed as limiting the scope of the disclosedsubject matter, as claimed. Thus, it will be apparent to one skilled inthe art that aspects of the disclosed fold out ramp may be employed withother ramp assemblies used in stationary installations, such asresidential buildings and the like. The following detailed descriptionmay use illustrative terms such as vertical, horizontal, front, rear,curbside (inboard), roadside (outboard), inner, proximal, distal, etc.;however, these terms are descriptive in nature and should not beconstrued as limiting. Further, it will be appreciated that variousembodiments of the disclosed fold out ramp may employ any combination offeatures described herein.

FIGS. 1-4 illustrate one exemplary embodiment of a fold out rampassembly 100 (hereinafter “ramp assembly 100”) as it moves from a stowedposition (FIG. 1) through a neutral position (FIG. 2), and a firstdeployed position (FIG. 3) to a second deployed position (FIG. 4). Theramp assembly 100 includes a frame 102, a ramp portion 110, anintermediate panel 130, and an inner panel 150. The frame 102 of theramp assembly 100 is adapted to be mounted to a vehicle (not shown)having a floor, such as a bus or a van. The ramp assembly 100 isreciprocal between the stowed position, shown in FIG. 1, and variousdeployed positions, such as the ones shown in FIGS. 3 and 4. In thestowed position, the ramp portion 110 is located such that the ramp isdisposed over the intermediate panel 130 and the inner panel 150, andthe lower surface 112 of the ramp portion faces upward and issubstantially coplanar, i.e., flush, with the floor (not shown) of thevehicle. In a deployed position, the ramp portion 110 extends in acurbside and downward direction to contact an alighting surface 90, suchas a curb or road surface, thus cooperating with the intermediate panel130 and inner panel 150 to provide a transition between the vehicle andthe alighting surface 90.

Although the illustrated embodiments of the ramp assembly 100 include aframe 102, other embodiments are contemplated in which the ramp assembly100 does not include a frame. To install such embodiments in vehicles,the ramp assembly 100 components can be attached directly to thestructure of the vehicle or to a suitable structure within the vehicle,thus making a frame 102 unnecessary. Similarly, when such embodimentsare installed in stationary installations, such as residential buildingsand the like, the ramp assembly 100 components can be attached to thestructure of the building or any other suitable structure within thebuilding. Accordingly, embodiments of the described ramp assembly 100that do not include a frame should be considered within the scope of thepresent disclosure.

Still referring to FIGS. 1-4, the ramp portion 110 includes a panel 114constructed from well-known materials. The ramp portion 110 furtherincludes side curbs 116 that extend upwardly from the forward and rearsides of the panel 114. The side curbs 116 increase the strength of theramp portion 110 and provide edge guards for the sides of the rampportion 110, thereby increasing the overall safety of the ramp assembly100. In the illustrated embodiment, the curbside end 118 of the rampportion 110 (when the ramp is in a deployed position) is tapered toprovide a smooth transition between the panel 114 and the alightingsurface 90 when the ramp assembly 100 is in a deployed position,although such a feature may not be necessary, depending on the thicknessof the ramp.

As shown in FIGS. 1-8, the ramp portion 110 is rotatably connected atthe roadside end 120 (when the ramp portion is in a deployed position)to the curbside end 132 of the intermediate panel 130 about an axis 170.Referring back to FIG. 3, the ramp portion 110 and the intermediatepanel 130 of the illustrated ramp assembly 100 are connected with asingle continuous hinge 172 i.e., a “piano hinge,” however, it will beappreciated that multiple hinges or any other configuration suitable forrotatably connecting the ramp portion 110 to the intermediate panel 130and/or maintaining a rotational association therebetween can beutilized.

The axis 170 maintains a generally horizontal orientation so that theramp portion 110 is rotatable about the axis to reciprocate between thestowed position and the deployed positions. In the stowed position,shown in FIG. 1, the ramp portion 110 extends inwardly from the axis 170such that the ramp is at least partially disposed over the intermediatepanel 130 and the inner panel 150. When in the stowed position, thelower surface 112 of the ramp panel 114 faces upward and is oriented tobe generally flush with the vehicle floor, thereby providing a surfaceupon which able-bodied passengers can walk while entering and exitingthe vehicle. When the ramp portion 110 is in a deployed position, suchas the one shown in FIG. 4, the ramp extends in an outward and downwarddirection so that the upper surface 122 of the panel 114 faces up andprovides an inclined transition surface from the intermediate panel 130to the alighting surface 90.

Referring now to FIGS. 5-8, the inner panel 150 is configured toreciprocate between a lowered position (FIG. 5), when the ramp assembly100 is in the stowed position and a raised position (FIG. 8), when theramp assembly is in a deployed position. In the disclosed embodiment,the inner panel 150 is supported by an inner panel support 156 disposedbeneath the inner panel. The inner panel support 156 includes aplurality of elongate members 158, each elongate member having aroadside end 160 and a curbside end 162. The roadside end 160 of eachelongate member 158 forms an angle with the curbside end 162 of thatelongate member that approximates the angle between the inner panel 150,and the intermediate panel 130 when the ramp assembly 100 is in adeployed position.

The inner panel support 156 is configured for rotating movement at thecurbside end about an axis 176. In the illustrated embodiment, thecurbside end 162 of each of the elongate members 158 is rotatablyconnected to the frame 102; however, any portion of the inner panelsupport can be coupled to any suitable structure to enable reciprocatingmovement of the inner panel 150 between the raised position and thelowered position.

The roadside end of the inner panel support 156 supports the inner panel150 and is itself supported by a selectively rotatably eccentric bearingelement 164. A bearing surface 166 is disposed on a lower portion of theinner panel support 156 to engage the eccentric bearing element 164. Asthe eccentric bearing element 164 is selectively rotated about its axis180, the bearing element engages the bearing surface 166 to raise andlower the roadside end on the inner panel support 156.

As shown in FIG. 5, when the ramp assembly 100 is in the stowedposition, the eccentric bearing element 164 is in a first position,wherein the inner panel support 156 is in a lowered position, and theinner panel 150 is disposed within the frame 102 and positioned belowthe ramp portion 110. As the ramp assembly 100 moves toward a deployedposition, the eccentric bearing element 164 rotates to lift the roadsideend of the inner panel support 156, thereby rotating the inner panel 150about axis 176 to a raised position. When the inner panel 150 is in theraised position, the upper surface of the inner panel is generallyhorizontal and coplanar, i.e., flush, with the vehicle floor. When theramp assembly moves from a deployed position to the stowed position, theeccentric bearing element 164 rotates back to the first position,thereby lowering the inner panel 150.

It should be appreciated that the illustrated mechanism for raising andlowering the inner panel 150 is exemplary and that alternativeconfigurations are possible. In this regard, the number and locations ofthe eccentric bearing elements 164 can vary. Further, the profile of thecam surface of the eccentric bearing element 164 can be modified tochange the movement of the inner panel as the ramp assembly 100reciprocates between the stowed and deployed positions. It should alsobe appreciated that the mechanisms are not limited to eccentric bearingsand cams, but can also include any number of different linkages. In onenon-limiting example, a four-bar linkage is coupled to one or more innerpanel supports 156 to raise and lower the inner panel 150. In anothercontemplated embodiment, one or more pins extend laterally from one ormore rotatable links to support the inner panel supports. Rotation ofthe links moves the pins along an arcuate path to raise and lower theinner panel. While the described configurations are all adaptable to bedriven by the drive assembly 230 described below, alternativeconfigurations in which a separate actuator raises and lowers the innerpanel 150 are also possible. These and other suitable configurations forraising and lowering the inner panel 150 are contemplated and should beconsidered within the scope of the present disclosure.

As shown in FIGS. 5-8, the intermediate panel 130 is constructed fromwell-known materials, and has an upper surface suitable for providing atransition surface from the inner panel 150 to the ramp portion 110 whenthe ramp assembly 100 is in a deployed position. As previously noted,the curbside end 132 of the intermediate panel 130 is rotatablyconnected to the ramp portion 110 about axis 170. The roadside end 134of the intermediate ramp 130 is rotatably associated with the curbsideend 154 of the inner panel 150.

In the illustrated embodiment, the intermediate panel 130 is supportedby an intermediate panel support 136 disposed beneath the intermediatepanel. The roadside end of the intermediate panel support 136 isrotatably coupled to the inner panel support 156 about an axis 184 sothat as the ramp assembly 100 reciprocates between the stowed positionand a deployed position, the angle between the upper surface of theinner panel 150 and the upper surface of the intermediate panel 130changes. In an alternate embodiment, the roadside end 134 of theintermediate panel 130 is coupled directly to the curbside end 154 ofthe inner panel 150 with a continuous hinge, or series of hinges. These,and other suitable configurations for establishing a rotationalrelationship between the inner panel 150 and the intermediate panel 130,are contemplated and should be considered within the scope of thepresent disclosure.

Still referring to FIGS. 5-8, the intermediate panel support 136includes a support member 190 extending downwardly from the curbside endof the intermediate panel support. During a first phase of deployment(FIGS. 5-7) the support member 190 selectively engages a latch mechanism200 (FIG. 11) that is fixedly positioned relative to the frame 102. Whenthe support member 190 is so engaged, the support member maintains theaxis 170 about which the ramp portion 110 is connected to theintermediate panel 130 in a substantially fixed location. Although theaxis 170 is maintained in a substantially fixed position, it will beappreciated that the axis 170 does move slightly as the intermediatepanel 130 moves in response to the movement of the inner panel 150between the raised and lowered positions.

During a second phase of deployment (FIGS. 7-8), the latch mechanism 200selectively disengages the support member 190. With the support member190 disengaged from the latch mechanism 200, continued actuation of theramp portion 110 toward a deployed position rotates the ramp portion 110about its curbside end 118. As a result, the axis 170 about which theramp portion 110 is connected to the intermediate panel 130, moves in adownward direction until the intermediate panel reaches a predeterminedposition. In the predetermined position, the intermediate panel 130 issupported by the inner panel support 156. More specifically, when theintermediate panel 130 is in the predetermined position, theintermediate panel engages the elongate members 158 of the inner panelsupport 156. These portions of the inner panel support 156 maintain theintermediate panel 130 in the predetermined position when the rampportion moves through the second phase of the deployment. It should beappreciated that the present disclosure is not limited to a particularconfiguration for maintaining the intermediate panel in a predeterminedposition. In this regard, any number and types of restraints andsupports can be utilized to maintain the intermediate panel 130 in thepredetermined position when the ramp portion is in a deployed position,and such alternate configurations should be considered within the scopeof the present disclosure.

Referring to FIGS. 9 and 10, one embodiment of a latch mechanism 200 isshown. The latch mechanism 200 includes a C-shaped catcher 202 rotatablycoupled to the frame 102 to selectively retain a pin 204 that forms partof the support member 190. The catcher 202 is rotatable between anengaged position (FIG. 9) and a released position (FIG. 10). In theengaged position, the pin 204 is at least partially disposed within arecess 212 formed in the catcher 202.

The latch mechanism 200 further includes a pawl 206 to selectivelyengage a notch 208 formed in the catcher 202. As shown in FIGS. 9 and10, the pawl 206 is rotatably coupled to the frame 102 proximate to thecatcher 202 and is biased to contact the pawl by a spring 210. With thelatch mechanism in the engaged position, the pawl 206 engages the notch208 to prevent the catcher 202 from rotating toward the releasedposition. At the same time, a pin 216 engages the catcher 202 to preventfurther rotation away from the released position. Thus, as shown in FIG.9, the pin 216 and the pawl 206 cooperate to lock the catcher 202 in theengaged position.

To unlock the latch mechanism 200, an actuator 214 (FIG. 11), which isoperably coupled to the pawl 206, temporarily rotates the pawl in aclockwise direction as viewed in FIGS. 9 and 10 so that the pawldisengages from the notch 208 formed in the catcher 202. With the pawl206 disengaged from the notch 208, the catcher 202 is free to rotatetoward the disengaged position, thereby releasing the support member190. With the support member 190 released from the latch mechanism 200,the curbside end 132 of the intermediate panel 130 is free to move to alowered position as the ramp assembly 110 moves through the seconddeployment phase. Once the catcher 202 has rotated to the disengagedposition, the actuator 214 releases the pawl 206, and the spring 210biases the pawl back to engage a side of the catcher. The pawl 206remains in sliding contact with the catcher 202 until the catcherreturns to the engaged position, at which time the pawl engages thenotch 208 to lock the catcher in the engaged position.

Still referring to FIGS. 9 and 10, when the ramp assembly 100 moves fromthe deployed position toward the stowed position, movement of the rampportion 110 drives the support member 190 upward so that the pin 204engages the recess 212 in the catcher 202 to rotate the catcher 202toward the engaged position. When the catcher 202 reaches the engagedposition, pin 216 engages the catcher to prevent further rotation. Atthe same time, the spring-loaded pawl 206 rotates back to engage thenotch 208 in the catcher 202, thereby locking the latch mechanism 200 inthe engaged position. In this manner, the pin 216 and the pawl 206cooperate to retain the catcher 202 in the engaged position, therebymaintaining the axis 170, about which the ramp portion 110 andintermediate panel 130 are connected, in a generally fixed position.

As previously described, the latch mechanism 200 maintains the axis 170in a fixed position during the first deployment phase, and allows theaxis 170 to move in a downward direction during the second deploymentphase. It will be appreciated that other configurations to selectivelymaintain the location of the axis 170 are possible. In one alternateembodiment, the curbside end of the intermediate panel 130 is supportedby a rotatable cam. The profile of the cam surface is such that as theramp assembly 100 initially moves from the stowed position, the camsupports the intermediate panel 130 in a fixed position, i.e., the camprofile has a constant radius during the first deployment phase. As theramp assembly 100 begins the second deployment phase, the cam surfacedisengages the intermediate panel so that the cam no longer supports theintermediate panel. As a result, the axis 170 is free to move in adownward direction during the second deployment phase, as describedabove.

In another contemplated embodiment, a Geneva drive is utilized toreciprocate one or more support elements between engaged and disengagedpositions. During the first deployment phase, the support elements arein the engaged position and support the curbside end of the intermediatepanel to maintain the axis 170 in a generally fixed position. During thesecond deployment phase, the support elements move to a disengagedposition so that the axis 170 is free to move downward. The Genevadrive, which translates continuous rotation into intermittent rotarymotion, allows for the support elements to be driven between twopositions by the constant rotary motion provided by the drive assembly230 described below. In this manner, the support elements arereciprocated between an engaged position (supporting the intermediatepanel) and a disengaged position (not supporting the intermediatepanel), wherein each position is generally fixed throughout the firstand second deployment phases, respectively.

In yet another contemplated embodiment, a separate actuator reciprocatessupport elements between engaged and disengaged positions. The supportelements operate in a similar manner to those described above in theembodiment that utilizes a Geneva drive; however, rather than utilizethe rotary motion of the drive assembly 230 described below, a separateactuator drives the support elements between the engaged and disengagedpositions. These and other configurations to selectively maintain theposition of the axis 170 are contemplated and should be consideredwithin the scope of the present disclosure.

Referring now to FIGS. 1-4, and 11, a drive assembly 230 actuates theramp portion 110 to reciprocate between the stowed position and adeployed position. A forward portion of the drive assembly 230 islocated on the forward side of the frame 102, and a rear portion of thedrive assembly is similarly located on the rear side of the frame 102,wherein each element of the forward portion of the drive assembly 230corresponds to a similar element of the rear portion of the driveassembly. For the sake of clarity, the forward portion of the driveassembly 230 is described herein with the understanding that unlessotherwise indicated, each element of the forward portion has acorresponding element on the rear portion of the drive assembly 230.

As shown in FIG. 11, the drive assembly 230 includes a roadside sprocket232 that is rotatably coupled to the roadside end of the forward side ofthe frame 102, so that the axis of rotation of the roadside sprocket 232extends in the forward/rearward direction. The drive assembly 230 alsoincludes a curbside sprocket 234 that is rotatably coupled to thecurbside end of the forward side of the frame 102 to have an axis ofrotation that is substantially parallel to the axis of rotation of theroadside sprocket 232. A drive chain assembly 236 forms an endless loopthat engages the teeth of the curbside sprocket 234 and the teeth of theroadside sprocket 232. As a result, movement of the drive chain assembly236 along the path of the endless loop rotates the roadside sprocket 232and the curbside sprocket 234.

A drive shaft 238 is coupled to the roadside sprocket 232 and also to amotor 240 (rotary actuator) by a well-known transmission assembly 242.The motor 240 is selectively operated to rotate the roadside sprocket232, thereby moving the roadside sprocket 232 and the curbside sprocket234 via the drive chain assembly 236. In one embodiment, a single motor240 drives the roadside sprocket 232 of the forward portion of the driveassembly 230 and also the drive sprocket of the rear portion of thedrive assembly 230. In another embodiment, each roadside sprocket 232 isdriven by a separate motor 240. In other alternate embodiments, thedrive shaft 238 connects the motor 240 to the curbside sprocket 234, orto a separate drive sprocket that engages the drive chain assembly 236.

One or more idler sprockets may be included in the drive assembly 230.The optional idler sprockets engage the drive chain assembly 236 toredirect the drive chain assembly 236 along a predetermined path. In oneembodiment, the drive chain assembly 236 includes a turnbuckle that isselectively adjustable to increase or decrease the length of the drivechain assembly 236 in order to adjust the tension of the drive chainassembly.

It should be appreciated that the present disclosure is not limited tothe illustrated motor, which is shown as providing a rotary output, butcan incorporate several other types of actuators. In one alternateembodiment, a linear actuator is utilized to drive the ramp assemblybetween the stowed and deployed positions. For such an embodiment, asuitable mechanism for converting linear motion into rotary motion isutilized. Non-limiting examples of such a mechanism include a rack andpinion system and a linkage. Further, the present disclosure is notlimited to electric motors (actuators), but can also include hydraulicsystems or any other suitable mechanism for providing a driving force toreciprocate the ramp assembly between the stowed and deployed positions.

As illustrated in FIGS. 12-15, a drive arm 250 is fixedly coupled toextend radially from the curbside sprocket 234. The drive arm 250includes an elongate slot 252 formed therein. A bearing element 254 iscoupled to the ramp portion and is at least partially disposed withinthe slot 252. As the drive assembly rotates the curbside sprocket 234,the drive arm 250 engages the bearing element 254 to apply a moment tothe ramp portion, thereby driving the ramp portion between the stowedposition (FIG. 12) and a deployed position (FIG. 15).

The slot 252 and bearing element 254 configuration allows the drive arm250 to drive the ramp portion 110 even though the axis of rotation 170of the ramp portion is not coincident with the axis of rotation 182 ofthe drive arm 250. Moreover, this configuration allows for the relativepositions of the axes 170 and 182 to change as the ramp assembly 100moves through the first and second deployment phases. It should beappreciated that alternate configurations for engaging the drive arm 250with the ramp portion 110 are possible. In one alternate embodiment, thebearing element is disposed on the drive arm 250 and engages a slotformed in the ramp portion. This and other alternate embodimentssuitable for coupling the drive arm 250 to the ramp portion to drive theramp portion between the stowed position and a deployed position arecontemplated and should be considered within the scope of the presentdisclosure.

As shown in FIG. 11, the eccentric bearing element 164 is coupled to thedrive shaft 238 so that rotation of the drive shaft rotates theeccentric bearing element 164 to raise and lower the roadside end 152 ofthe inner panel 150. As a result, rotation of the drive shaft 238 movesboth the eccentric bearing element 164 and the drive arm 250 so thatmovement of the inner panel 150 and the ramp portion 110 aresynchronized.

Referring to FIGS. 1-4, the drive assembly 230 further includes acounterbalance assembly 260. The counterbalance assembly 260 can be anyknown counterbalance assembly that biases the ramp portion toward theneutral position, i.e., a position wherein the center of gravity of theramp portion 110 is located above the axis of rotation 170 of the rampportion, so that the center of gravity imparts no moment about the axisof rotation. By biasing the ramp portion 110 toward the neutralposition, the counterbalance assembly counteracts some or all of theweight of the ramp, thereby reducing the actuating force required toreciprocate the ramp assembly 100 between the stowed position and adeployed position. As a result, a smaller motor is required, and wear onthat motor is reduced. One exemplary counterbalance suitable for usewith the ramp assembly is disclosed in U.S. Pat. No. 7,681,272, issuedto Morris et al., which is incorporated by reference herein. It will beappreciated that the counterbalance of Morris et al. is only oneexemplary counterbalance suitable for use with the presently disclosedramp assembly, and that any number of other suitable counterbalanceassemblies can by utilized in conjunction with or in place of thereferenced counterbalance.

As previously noted, when the ramp assembly 100 is in the stowedposition, the ramp portion 110 is located such that the ramp portion ispositioned over the intermediate panel 130 and the inner panel 150, andthe lower surface 112 of the ramp portion 110 faces upward and issubstantially coplanar, i.e., flush, with the floor (not shown) of thevehicle. When the ramp assembly 100 is in the stowed position, theintermediate panel 130 and the inner panel 150 are disposed within theframe 102. In the exemplary embodiment shown in FIG. 5, when the rampassembly 100 is in the stowed position, the intermediate panel 130 andthe inner panel 150 are positioned so that the upper surfaces of thepanels 130 and 150 are generally oriented such that the roadside end ofeach panel is lower than the curbside end of that panel. It should beappreciated that the orientation of the intermediate panel 130 and theinner panel 150, relative to each other and to the frame 102 of the rampassembly 100 when the ramp assembly, is in the stowed position may varywithout departing from the scope of the disclosure.

Referring to FIGS. 1-10, the deployment motion of the ramp assembly 110includes a first phase and a second phase. During the first phase, theramp assembly 110 moves from the stowed position (FIGS. 1 and 5) to afirst deployed position (FIGS. 3 and 7). As the ramp assembly 110travels through the first phase, the support member 190 remains engagedwith the locked latch mechanism 200. As a result, the axis 170 aboutwhich the ramp portion 110 is coupled to the intermediate panel 130maintains a generally fixed location; although some movement of the axis170 occurs as the intermediate panel rotates about the pinned connectionto the latch mechanism 200.

To drive the ramp assembly 100 through the first phase, the motor 240rotates the drive shaft 238 in a first direction to rotate both thedrive arm 250 and the eccentric bearing element 164. As shown in FIGS.12-15, rotation of the drive arm 250 rotates the ramp portion 110 aboutaxis 170. At the same time, the eccentric bearing element 164 rotates toraise the roadside end 152 of the inner panel 150, thereby moving theinner panel from a lowered position to a raised position.

In the disclosed embodiment, the first deployment phase ends when theramp portion 110 has rotated through a predetermined angle about axis170. To determine the travel and, thus, the position of the ramp, asensor (not shown) detects the position of the drive shaft 238. Itshould be appreciated that the type and position of the sensor is notlimited to one that detects the position of the drive shaft 238, but caninclude sensors associated with the ramp portion 110, other parts of thedrive system, the intermediate panel, the inner panel, or any othersuitable portion of the ramp assembly.

As shown in FIG. 7, when the ramp assembly 100 is located in the firstdeployed position at the end of the first deployment phase, theintermediate panel 130 and the inner panel 150 have generally horizontalupper surfaces. The ramp portion 110 extends outward and downward towardthe alighting surface 90. If the alighting surface 90 is a curb havingsufficient height, the ramp portion 110 will contact the alightingsurface, and the slope of the ramp portion 110 may be gradual enoughthat further deployment of the ramp assembly 100 through the secondphase is unnecessary.

The second deployment phase begins when the actuator 214 rotates thepawl 206 to unlock the latch mechanism 200. Unlocking the latchmechanism 200 allows the support member 190 to disengage from thecatcher 202. This, in turn, allows the curbside end 132 of theintermediate panel 130 and, therefore, axis 170 to move in a downwarddirection. If the ramp portion 110 is not already in contact with thealighting surface 90 when the ramp assembly is in the first deployedposition and the latch mechanism is unlocked, then the weight of theramp portion creates a moment about the bearing element 254 that tendsto lift the curbside end 132 of the intermediate panel 130. As a result,the support member 190 remains engaged with the latch mechanism 200, andthe ramp portion continues to rotate about generally fixed axis 170until the ramp portion contacts the alighting surface 90.

Once the curbside end 118 of the ramp portion 110 contacts the alightingsurface 90, either in the first deployed position or after the rampportion has rotated through an initial part of the second deploymentphase, further rotation of the drive arm 250 about axis 182 drives thebearing element 254 to rotate the ramp portion 110 about its curbsideend 118. As the ramp portion 110 rotates about its curbside end 118, thehinge axis 170 moves in a downward direction, driving the support member190 so that it disengages from the unlocked latch mechanism 200. Thus,the ramp portion 110, which rotated in a first direction relative to theintermediate panel 130 during the first deployment phase, now rotates ina second direction, opposite the first direction, relative to theintermediate panel during the second deployment phase. As a result, theramp portion 110 and the intermediate panel 130, which are positionedrelative to each other to form an angle of greater than 180° in thefirst deployed position, move such that the angle formed therebetweenapproaches approximately 180° when the ramp assembly 100 is in thesecond deployed position.

With the ramp portion 110 and the intermediate panel 130 forming anangle of approximately 180°, the ramp portion and the intermediate panelcooperate to provide a substantially flat transition surface from theinner panel 150 to the alighting surface 90. Although the ramp portion110 and the intermediate panel 130 of the disclosed ramp assembly 100form an angle of approximately 180° in the second deployed position, thedistance between the vehicle floor and the alighting surface, roadcrown, the inclusion of a “kneeling” feature on the vehicle, the lengthof the ramp portion, and other factors can affect relative positions ofthe ramp portion and the intermediate panel in the second deployedposition. Accordingly, it should be understood that the angle betweenthe ramp portion 110 and the intermediate panel 130 in the seconddeployed position can vary. These and other variations in theconfiguration of the deployed ramp assembly are contemplated and shouldbe considered within the scope of the disclosed subject matter.

In the illustrated embodiment, the second deployed position is reachedwhen the intermediate panel 130 has achieved a predetermined anglerelative to the inner panel 150. This predetermined angle is reachedwhen the intermediate panel 130 contacts portions of the inner panelsupport 156 as shown in FIG. 8. In this manner, the inner panel support156 acts as a stop to limit the downward travel of the hinge axis 170during the second phase and also provides support to the intermediatepanel 130 when the ramp assembly 100 is in a fully deployed position.

To move the ramp assembly 100 from a deployed position to the stowedposition, the motor 240 rotates the drive shaft 238 in a reversedirection. This rotation moves the drive arm 250 to raise the curbsideend 132 of the intermediate panel 130 until the support member 190engages the latch mechanism 200. With the position of curbside end 132of the intermediate panel 130 generally fixed by the latch mechanism200, further rotation of the drive arm 250 rotates the ramp portion 110about axis 170 until the ramp portion has returned to the stowedposition. As the drive arm 250 drives the ramp portion 110 toward thestowed position, the eccentric bearing element 164 rotates to lower theroadside end 152 of the inner panel 150 until the inner panel hasreturned to its lowered position.

Referring now to FIGS. 16-23B, a ramp assembly 100 with an alternativedrive assembly 230 is illustrated. The illustrated embodiment is similarto the previously described embodiment, but instead uses a linkage 270to transfer the driving force from the motor 240 (actuator) to the rampportion 110. Similar to the previously described embodiment, a drive arm272 is fixedly coupled to the curbside sprocket 234. The drive arm 272extends radially from the curbside sprocket 234 so that the drive armrotates with the curbside sprocket 234 about a common axis of rotation.

The drive arm 272 is connected to the ramp portion 110 by a link 274that is rotatably coupled at one end to the drive arm 272 and at theother end to the ramp portion 110. The linkage 270 formed by the drivearm 272 and the link 274 is a scissor-type linkage that is capable ofproviding a driving force to the ramp portion from the motor 240. As thedrive assembly rotates the curbside sprocket 234, the drive arm 272drives the link 274 to apply a moment to the ramp portion, therebyreciprocating the ramp portion between the stowed position (FIG. 20A)and a deployed position (FIG. 23A). Moreover, as shown in FIGS. 20A,21A, 22A, and 23A, the angle between the drive arm 272 and the link 274changes throughout the ramp motion to account for the fact that the rampportion 110 and the drive arm 272 rotate about different axes.

It should be appreciated that the illustrated linkage is exemplary onlyand should not be considered limiting. In this regard, the position andlengths of the drive arm 272 and link 274 can vary. In addition,alternate linkage configurations that utilize one or more additionalrotating or sliding links, or any other known linkage configuration canbe utilized to drive the ramp portion 110. Further, the linkage need notbe coupled to a sprocket, but can be coupled to a rotary or linearactuator either directly or indirectly using a known transmissionconfiguration. These and other alternate embodiments suitable forcoupling a linkage to the ramp portion to drive the ramp portion betweenthe stowed position and a deployed position are contemplated and shouldbe considered within the scope of the present disclosure.

Referring now to FIGS. 18, 19, 20B, 21B, 22B, and 23B, a cam surface 300is formed on the upper edge of the roadside end 120 (when the ramp is ina deployed position) of each of the side curbs 116. A corresponding camfollower 302 is mounted to each side of the ramp assembly 100 about anaxis that maintains a fixed position relative to the vehicle. In theillustrated embodiment, the cam follower 302 is a roller bearingrotatably mounted about the axis of rotation 182 of the drive arm 272.

As best shown in FIG. 20B, when the ramp assembly 100 is in the stowedposition, the cam follower 302 is engaged with the cam surface 300 tosupport the roadside end 120 of the ramp portion 110. Because the camfollower 302 is secured about an axis that is fixed relative to thevehicle, the engagement of the cam follower 302 with the cam surface 300provides added stability to the ramp panel 114, thereby limitingmovement of upward facing lower surface 112 of ramp panel 114 aspassengers step on the ramp assembly 100. As the ramp assembly 100 movesfrom the stowed position to the deployed position, the motion of theramp portion 110 moves the cam surface 300 such that the cam follower302 disengages from the cam surface. (See FIGS. 21B, 22B, and 23B.) Theillustrated exemplary embodiment of the ramp assembly is described withthe understanding that alternate embodiments exist within the scope ofthe present disclosure. In one alternate embodiment, the ramp assemblydoes not include a movable inner panel. Instead, the inner panelmaintains a fixed position relative to the vehicle floor through theentire ramp motion. For such an embodiment, an eccentric bearing memberis not required. In another alternate embodiment, the ramp assembly doesnot include an inner panel; instead, the intermediate panel is rotatablyassociated with the floor of the vehicle.

Another alternate embodiment of the disclosed ramp assembly uses one ormore separate actuators to drive the motion of the ramp through thesecond deployment phase, i.e., to lower the hinged connection betweenthe ramp portion and the intermediate panel. Moreover, the actuator oractuators are not limited to the disclosed electric motor. One of skillin the art will appreciate that the ramp assembly can be modified to usea number of different types of actuators, including linear actuators,pneumatic actuators, hydraulic actuators, and any other suitable devicesfor moving the ramp assembly through the deployment motion.

Various embodiments utilizing different control methods are alsocontemplated. In one embodiment, an operator activates a single switchto deploy and stow the ramp assembly 100. When the switch is activated,the ramp assembly deploys through the first and second deployment phasesregardless of the distance between the alighting surface and the vehiclefloor. In one alternate embodiment, sensors detect when the ramp portioncontacts the alighting surface and, based on the slope of the rampportion at that position, a controller determines whether or notdeployment through the second deployment phase is necessary. In yetanother possible embodiment, the operator selectively activates one oftwo switches, depending on the type of alighting surface. If thealighting surface is a curb, the operator activates the correspondingswitch, and the ramp portion moves through the first deployment phaseuntil the ramp portion contacts the curb. If the alighting surface is aroad, then the operator activates the second switch, and the rampassembly deploys through the first and second deployment phases toprovide a transition surface between the road and the vehicle floor. Inyet another contemplated embodiment, the operator can selectivelycontrol the rotation of the drive arm 250 and the release of thelatching mechanism 200 to control the ramp assembly so that the rampportion and the intermediate panel, respectively, are at desiredorientations throughout the deployment of the ramp assembly.

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the disclosed subject matter.

The invention claimed is:
 1. A ramp assembly for a providing atransition surface from a vehicle floor to an alighting surface, theramp assembly comprising: (a) a ramp portion coupled for reciprocatingmovement between a stowed position and a deployed position, the rampportion having a cam surface disposed thereon; (b) a cam follower havinga first axis fixedly located relative to the vehicle floor, the camfollower engaging the cam surface when the ramp portion is in the stowedposition to support the ramp portion; (c) a panel, a first end of thepanel being rotatably coupled to a first end of the ramp portion about asecond axis; (d) a drive arm rotatable about a third axis and operablycoupled to the ramp portion; and (e) an actuator operably coupled to thedrive arm to rotate the drive arm about the third axis, rotation of thedrive arm driving the ramp portion through a first phase and a secondphase of a deployment motion, wherein: (i) the first phase comprises thedrive arm rotating the ramp portion about the second axis, wherein thesecond axis maintains a substantially fixed position; and (ii) thesecond phase comprises the drive arm moving the second axis in adownward direction, wherein the second phase is subsequent to the firstphase.
 2. The ramp assembly of claim 1, wherein the cam followerdisengages from the cam surface during the first phase. surface duringthe second phase.
 3. The ramp assembly of claim 2, wherein the camfollower is disengaged from the cam surface during the second phase. 4.The ramp assembly of claim 1, further comprising a link, a first end ofthe link being rotatably coupled to the drive arm, a second end of thelink being rotatably coupled to the ramp portion.
 5. The ramp assemblyof claim 1, wherein the ramp portion comprises a bearing element atleast partially disposed within a slot formed in the drive arm, thedrive arm engaging the bearing element to reciprocate the ramp portionbetween the stowed position and the deployed position.
 6. The rampassembly of claim 1, wherein the drive arm comprises a bearing elementat least partially disposed within a slot formed in the ramp portion,the bearing element engaging the ramp portion to reciprocate the rampportion between the stowed position and the deployed position.
 7. A rampassembly, comprising: (a) a ramp portion coupled for rotational movementbetween a stowed position and a deployed position, the ramp portioncomprising a side curb with a cam surface disposed thereon; (b) a panel,a curbside end of the panel being rotatably coupled to the ramp portionabout a first axis; (c) an elongate drive arm extending radially from asecond axis, the drive arm being operably coupled to the ramp portion;(d) an actuator operably coupled to the drive arm to rotate the drivearm about the second axis, rotation of the drive arm moving the rampportion through a deployment motion, the deployment motion comprising:(i) a first phase, wherein the drive arm rotates the ramp portion aboutthe first axis; and (ii) a second phase, wherein the drive arm moves thefirst axis from a raised position to a lowered position; and (e) a camfollower having an axis fixedly positioned relative to the vehiclefloor, the cam follower engaging the cam surface when the ramp portionis in the stowed position to support the ramp portion.
 8. The rampassembly of claim 7, wherein the cam follower disengages from the camsurface during the first phase.
 9. The ramp assembly of claim 8, whereinthe cam follower is disengaged from the cam surface during the secondphase.
 10. The ramp assembly of claim 7, further comprising a link, afirst end of the link being rotatably coupled to the drive arm, a secondend of the link being rotatably coupled to the ramp portion.
 11. Theramp assembly of claim 7, wherein the ramp portion comprises a bearingelement at least partially disposed within a slot formed in the drivearm, the drive arm engaging the bearing element to reciprocate the rampportion between the stowed position and the deployed position.
 12. Theramp assembly of claim 7, wherein the drive arm comprises a bearingelement at least partially disposed within a slot formed in the rampportion, the bearing element engaging the ramp portion to reciprocatethe ramp portion between the stowed position and the deployed position.13. A ramp assembly for a providing a transition surface from a vehiclefloor to an alighting surface, the ramp assembly comprising: (a) a rampportion coupled for reciprocating movement between a stowed position anda deployed position, the ramp portion having a cam surface disposedthereon; (b) a cam follower fixedly located relative to the vehiclefloor, the cam follower engaging the cam surface when the ramp portionis in the stowed position to support the ramp portion, the cam followerbeing disengaged from the cam surface when the ramp portion is in adeployed position; and (c) a panel, a first end of the panel beingrotatably coupled to a first end of the ramp portion about an axis,wherein (1) the axis maintains a fixed position during a first phase ofa deployment motion; (2) the axis moves in a downward direction during asecond phase of the deployment motion. first panel, a curbside end ofthe first panel being rotatably coupled to a first end of the rampportion about a first axis;
 14. The ramp assembly of claim 13, whereinthe second phase is subsequent to the first phase.
 15. The ramp assemblyof claim 13, further comprising an actuator operably associated with theramp portion, the actuator driving the ramp portion through the firstand second phases of the deployment motion, wherein: (a) the actuatorrotates the ramp portion about the axis during the first phase; and, (b)the actuator moves the axis in a downward direction during the secondphase.
 16. The ramp assembly of claim 13, wherein the cam followerdisengages from the cam surface during the first phase.
 17. The rampassembly of claim 16, wherein the cam follower is disengaged from thecam surface during the second phase.
 18. A ramp assembly, comprising:(a) a ramp portion coupled for rotational movement between a stowedposition and a deployed position, the ramp position comprising a sidecurb with a cam surface disposed thereon; (b) a panel, a curbside end ofthe panel being rotatably coupled to the ramp portion about an axis; (c)an actuator operably associated with the ramp portion to drive the rampportion through a deployment motion, the deployment motion comprising:(i) a first phase, wherein the actuator rotates the ramp portion aboutthe axis; and (ii) a second phase, wherein the actuator moves the axisfrom a raised position to a lowered position; and (d) a cam followerfixedly positioned relative to the stowed position of the ramp position,the cam follower engaging the cam surface when the ramp portion is inthe stowed position to support the ramp portion.
 19. The ramp assemblyof claim 18, wherein the cam follower disengages from the cam surfaceduring the first phase.
 20. The ramp assembly of claim 19, wherein thecam follower is disengaged from the cam surface during the second phase.21. The ramp assembly of claim 18, wherein the axis maintains a fixedposition during the first phase of a deployment motion.